1. The Field of the Invention
The present invention relates to containers for use in the storing, dispensing, and packaging of food and beverage products. More particularly, the present invention is directed to both disposable and nondisposable food and beverage containers manufactured from inorganic aggregates and organic binders, which containers are lightweight, insulative, inexpensive, and/or more environmentally neutral than those currently used in the storing, dispensing (e.g., serving or portioning), and packaging food and beverage products. Disposable containers of the present invention are particularly useful for dispensing hot and cold food and beverages in the fast food restaurant environment.
2. Related Application
This patent application is a continuation-in-part of pending patent application Ser. No. 07/929,898, filed Aug. 11, 1992, for CEMENTITIOUS FOOD AND BEVERAGE STORAGE, DISPENSING, AND PACKAGING CONTAINERS AND THE METHODS OF MANUFACTURING SAME in the names of Per Just Andersen, Ph.D. and Simon K. Hodson (now abandoned).
3. Review of the Relevant Technology
The United States enjoys one of the safest food supplies in the world. Advanced processing and packaging techniques allow foods to travel safely for long distances from their point of origin. Even with lengthy and time consuming distribution systems, today's food products arrive more wholesome than foods in other places in the world where there are fewer and inferior processing and packaging options.
Packaging protects food from environmental influences and damage during distribution. It also provides a medium for the dissemination of information to the consumer like, for example, nutritional information, cooking instructions, ingredients, product weight, advertising, brand identification, and pricing.
Specifically, packaging protects foods from two major destructive influences: chemical and physical. Chemical protection is related to compositional changes resulting from exposure to gases (typically oxygen), moisture (either gain or loss of moisture can be damaging), light, or microorganisms. Although not strictly a chemical problem, packaging also provides a barrier against vermin, including rodents and insects.
On the other hand, protecting against physical destruction includes restricting the physical contents of the goods, cushioning against shock and vibration encountered during distribution, and preventing the items from leaking or being crushed. Many foods are transported in bulk and then prepared on site and dispensed to the end user by means of a disposable container, such as a cup, plate, or box (such as the "clam shell" frequently used in fast food restaurants). Traditionally, such disposable cups and other containers have been made from paper or plastic, e.g., styrofoam or other polystyrene-type materials. Every year, 5.6 billion tons of plastic packaging containers are produced.
Because hot items (such as drinks and fast food) require a container that is insulated to slow the flow of heat (both to keep the item hot and to protect the consumer from being burned or scalded) the container of choice in recent years has typically been made from styrofoam. Although paper or plastic coated containment products can be equipped with special handles, styrofoam containers have remained the far superior disposable container of choice when insulation is required, because of insulation capabilities, cost, and stability.
Recently, with the public's attention being more focused on environmental issues, certain containment products have come under heavy scrutiny, especially disposable cups and boxes. Most notably subject to criticism have been styrofoam products, which typically require the use of chlorofluorocarbons (or "CFC's") in their manufacture, as well as use of vast amounts of the ever shrinking petroleum reserves.
CFC's are relatively stable and inert and are widely used in a variety of important industrial and domestic activities, including refrigeration and the manufacture of styrofoam packing materials and containers. Both of these uses have been important in the storage and distribution of foods.
However, CFC's have been linked to the destruction of the ozone layer because they release chlorine products into the stratosphere. It is thought that the CFC molecule, which is very stable, eventually migrates upward through the atmosphere into the stratosphere. There it is bombarded by the sun's ultraviolet ("UV") radiation, which breaks the CFC molecule into its constituent atoms, including chlorine. The freed chlorine atoms form chlorine monoxide, which reacts with ozone (O.sub.3), a highly reactive form of oxygen, which is also produced by the photochemical action of the sun. Thus, the formation of ozone and the formation of ozone-depleting chlorine monoxide are competing reactions which are both catalyzed by UV radiation.
Studies conducted by the second North American National Ozone Expedition and the International Airborne Antarctic Ozone Experiment have linked high chlorine monoxide levels with a correspondingly high depletion of the ozone layer. The Ozone Trends Panel concluded that from 1969 to 1986, ozone levels had dropped from between about 1.7% to 3% in the latitude band 30.degree. to 64.degree. N, which covers most of the United States, Europe, the former Soviet Union, and China. Winter-time depletion in the northern portion of this region was even more severe, being from 5% to 6%.
The ozone layer is responsible for filtering the most harmful UV wavelengths emitted by the sun, and its depletion will undoubtedly lead to widespread damage to living organisms. Excessive exposure to UV radiation causes burning to the skin and retinas of humans and animals. One recent "ozone hole" reported over the southern tip of South America reportedly caused blindness, cataracts, and other UV radiation induced illnesses in cattle and sheep in Tierra del Fuego, the southernmost region of Chile and Argentina.
More generally, medical authorities have reported a 30% rise in skin cancer cases in the U.S. in the last decade, most of them due to sun exposure. There have been numerous studies and reports that have concluded that further breakdown of the ozone layer will lead to sharp increases in skin cancer and cataracts in humans.
While CFC's are utilized in a broad number of applications, according to a report prepared by the Environment Protection Agency ("EPA"), the making of foams such as those used in making some insulation materials accounted for roughly 25% of the total global use of CFC's in 1986. For this and other reasons, efforts have been directed to eliminate the use of CFC's. Several recent treaties, including the 1987 Montreal Protocol, have begun to mandate substantial cuts in the use of CFC's.
In the interim, manufacturers of some types of insulative foam have been turning to HCFC-22. While less ozone-depleting than CFC-12, HCFC-22 is still implicated. As a result, in the early 1990's, some companies have started to use pentane in the foaming process of plastics. Nevertheless, pentane is also very hazardous to the environment and is a greenhouse gas. Breathing pentane vapor can be hazardous.
Styrofoam containers have been widely used in the fast-food industry, for example, to hold coffee and other hot drinks, hamburgers, sandwiches, sushi, salads, fruit dishes, chinese food, pizza, ice cream and similar frozen food products, and almost any other dispensed fast food item imaginable. In particular, the "clam-shell" food container has been, and continues to be, the container of choice for many fast food vendors.
According to the Citizen's Clearinghouse for Hazardous Waste in Arlington, Va., the McDonald's fast-food chain alone, until recently, used 1.5 billion cubic feet of styrofoam each year for its food and drink containers. However, in response to environmental concerns, McDonald's has eliminated styrofoam from most of its containers in favor of traditional paper food wrappers and cups. Other large users of styrofoam containers and cups are considering similar reductions or eliminations of the use of such products.
In fact, there has been widespread clamor for companies to return to using more environmentally safe and low cost containers. Nevertheless, it is thought by some that the use of paper only represents the lesser of the two evils. Although paper products have not been linked to the destruction of the ozone layer, recent studies have shown that in other respects paper more strongly impacts the environment than does styrofoam. In fact, the wood pulp and paper industry is one of the top five polluters in the United States.
A 1991 study by Martin B. Hocking, a professor of chemistry at the University of Victoria, British Columbia compared the environmental impacts of paper versus polystyrene cups, from resource utilization, through manufacturing stages, to final disposal. He concluded that for single-use application, it appears that polystyrene foam cups are not necessarily more damaging to the environment than paper cups. Hocking's analysis indicated, for example, that since acquisition of the raw materials for production of paper cups included both the wood acquisition and a hydrocarbon acquisition equal to that required for polystyrene cups, production of paper cups results in a greater environmental impact.
Additionally, his study showed that six times as much wood pulp by weight as polystyrene is required to produce a cup; the paper cup consumes about 12 times as much steam, 36 times as much electricity, and twice as much cooling water in its manufacturing process than does a polystyrene foam cup. Even more significantly, about 580 times the volume of waste water is produced for the pulp required to make the paper cup.
The effluent from paper making contains 10 to 100 times the amount of contaminants produced in the manufacture of polystyrene foam. For each ton of bleached pulp, 22.7 kilograms of air pollutants are generated, compared with 53 kilograms for each ton of polystyrene. However, because it takes about six times more wood pulp to produce a cup than polystyrene, cup-for-cup polystyrene generates less air pollution.
In addition, the bleaching of wood pulp to form the paper that is incorporated into cups and other packaging containers results in the production of another extremely harmful and notorious by-product: i.e., dioxin. Dioxin, or more accurately, 2,3,7,8-tetrachlorodibenzo[b,e] [1,4]dioxin ("TCDD"), is a highly toxic and teragenic contaminant. According to the Merck Index, dioxin is extremely potent, being extremely dangerous in very low quantities.
Dioxin has been found in discharge waters from paper mills in concentrations of up to 0.5 parts per trillion. However, fish found downstream from paper pulp mills can contain nearly 200 parts per trillion of dioxin, with levels of 50 parts per trillion being not uncommon. Therefore, it appears that dioxin tends to concentrate itself in living tissue and is not metabolized or washed out of the body through dialysis.
Toxic effects of dioxin in animals include anorexia, severe weight loss, hepatotoxicity, hematoporphyria, vascular lesions, chloracne, gastric ulcers, teratogenicity, and premature death. Industrial workers exposed to TCDD have frequently developed chloracne, porphyrinuria, and porphyria cutanea tarda. Most experts in the field believe that dioxin is a carcinogen.
Recently, there has been considerable publicity directed at bleached paper cardboard food containers, which often contain trace amounts of dioxin that can contaminate the food they contain. Typical concentrations of dioxin in bleached paper products range from undetectable amounts up to about 10 parts per trillion.
As of 1989, milk packed in cardboard containers in the United States contained dioxin levels of several hundredths to nearly one part per trillion. Therefore, although milk containers are coated with a waterproofing material, this material is not impermeable and does not prevent the leaching of dioxin. It is estimated that the current daily intake of dioxin in the United States averages about 20.times.10.sup.-12 grams per kilogram of body weight. The FDA estimates that for every one million average milk drinkers in the United States, five will get cancer as a result of dioxin in milk containers.
Further, it is forgotten that it is often necessary to coat any paper container with a wax or plastic material in order to give it the desired waterproofing properties. Moreover, if insulative properties are necessary, even more drastic modifications to the paper material in the container are necessary.
As mentioned above, many types of plastic containers, as well as the coatings utilized with paper containers, are derived from fossil fuels, mainly petroleum, and share many of the environmental concerns of petroleum refinement and the petrochemical industry, which need not be repeated here.
In addition to the obvious chemical hazards of paper, plastic, and polystyrene production, an additional problem is the impact of these containers on municipal waste disposal systems throughout the country. Both polystyrene and plastics used in food containers are very slow to break down. This is especially true when buried deep inside of landfills, and away from the corrosive effects of light, air, and water.
Similarly, although paper is touted as biodegradable, this is hardly true for paper that is buried deep inside of municipal landfills away from light, moisture, and air. Paper can last a remarkably long time in a municipal dump, there being reports of telephone books being lifted from garbage that had been buried for decades. This longevity of paper is further complicated since it is commonly treated, coated, or impregnated with various organic materials.
Studies have shown that a typical garbage dump includes 41% paper and 7% plastic by weight. Food packaging of all materials accounts for about 12% of the total amount of municipal waste. These figures clearly indicate the significance of current packaging containers. Incineration could reduce these amounts, but incineration is often the source of significant airborne pollution, especially when plastics and polystyrene products are incinerated. Even paper, which burns relatively cleanly, emits dioxin as well as CO.sub.2 (which has been implicated as a greenhouse gas).
About the only effective way to reduce the sheer volume of packaging wastes would be to use more reusable containers or recycle disposable ones. However, recycling is not without its contribution of large amounts of pollution into the environment in the form of fuel spent in transporting recyclables to recycling centers, as well as fuels and chemicals used in the recycling process itself.
In short, what are needed are other food and beverage containers for storing, dispensing, and packaging which do not require the wholesale cutting of trees in order to supply the necessary raw materials. In addition, it would be a significant advancement in the art to provide food and beverage containers which are more environmentally neutral, such as minimizing the use of ozone-depleting chemicals, creation of unsightly garbage that does not, or is very slow to, degrade. It would be yet another improvement to provide food and beverage containers which do not contain hazardous chemicals like dioxin.
It would be a significant advancement to provide insulated food and beverage containers which have the insulating properties of styrofoam, but which do not contribute to the depletion of the ozone layer. Further, it would be significant if such food and beverage containers were lightweight, yet possessed sufficient structural support to hold or contain the food or beverage product in question.
From a practical point of view, such containers must necessarily be capable of being produced inexpensively at costs comparable to existing products. From a manufacturing perspective, it would be a significant advancement in the art to provide food and beverage containers which can be rapidly formed while maintaining their shape without external support so that the final molded product can be handled under ordinary manufacturing conditions.
Finally, it would be a completely novel and important advancement if such food and beverage containers were readily disposable like the disposable cups and containers currently used, but which had essentially the chemical composition of the earth in which they eventually will be disposed.
Such food and beverage containers are disclosed and claimed herein.